At a guess he's been dead for two days.

据猜测，他已经死了两天了。

At a guess , there were forty people at the party.

估计有四十人参加了聚会。

Everybody was at a guess about what would happen.

每个人都在猜测未来会发生什么。

At a guess I shall say we are speed at fifty miles an hour.

我猜测我们正以每小时五十公里的速度在前进。

At a guess, I should say we are speeding fifty miles and hour.

我猜测我们正以每小时五十公里的速度在前进。